<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>

</body>
<script>
  // var add = (a, b) => {
  //   console.log(a, b);
  //   return a + b;
  // }

  // var add = (a) => {
  //   console.log(a);
  //   return a;
  // }

  // var add = a => {
  //   console.log(a)
  //   return a * 10;
  // }

  // var add = (a = 10) => {
  //   console.log(a);
  //   return a;
  // }
  // var sum = console.log(add(1));

  // var say = () => {
  //   console.log('hello');
  // }

  var say = (a, d) => {
    console.log('hello', a, b);
  }
  // var sum = console.log(say(1, 2));

  var add = (a) => {
    return a * 10;
  }

  var add = a => a * 10;
  var fn = a => ({ num: a });
  var result = fn(100);
  console.log(result);

</script>

</html>